The present invention is related to a nanoparticle composition, a device including the nanoparticle composition, and a method thereof. It finds particular application in conjunction with a cloaking device, a biological sensing device, a drug delivery device, a meta material, a negative index material, an enhanced imaging device, and a device for solar energy conversion; and will be described with particular reference thereto. However, it is to be appreciated that the present exemplary embodiments are also amenable to other like applications.
Understanding and controlling the collective behavior of nanoparticles (NPs) is a challenging task of fundamental and practical importance. This is particularly true for nanorods (NRs) since their anisotropy implies additional functionality at the scale of individual particles and at the scale of their assemblies, which enable a variety of applications, from cloaking devices to biological sensing and solar energy conversion.
One approach for NR assembly is disclosed in B. Nikoobakht, Z. L. Wang, M. A. El-Sayed, J. Phys. Chem. B 2000, 104, 8635; and N. R. Jana, Angew. Chem. Int. Ed. 2004, 43, 1536. The approach reported therein relies on the Onsager (excluded volume) mechanism, driving parallel alignment of NRs when their volume fraction Φ and their aspect ratio are high enough. Another approach utilizes anisotropic attractive forces and thus can produce assembled structures at practically any concentration of NRs. For example, K. K. Caswell et al. disclose an end-to-end assembly of NRs with covalently bound biotin connected into chains by streptavidin (K. K. Caswell, J. N. Wilson, U. H. F. Bunz, C. J. Murphy, J. Am. Chem. Soc. 2003, 125, 13914). E. Dujardin et al. taught a side-by-side assembly of NRs with an oppositely charged B-DNA (E. Dujardin, L.-B. Hsin, C. R. C. Wang, S. Mann, Chem. Commun. 2001, 1264). Side-by-side assembly of NRs based on hydrophobic/hydrophilic interactions is disclosed in Z. Nie, D. Fava, E. Kumacheva, S. Zou, G. C. Walker, M. Rubinstein, Nature Mater. 2007, 6, 609; and B. P. Khanal, E. R. Zubarev, Angew. Chem. Int. Ed. 2007, 46, 2195.
Advantageously, this invention provides a nanoparticle composition, a device including the nanoparticle composition, and a method for making the same, which exhibit many merits such as a simplified process for achieving a desired geometry of nanoparticles assembly without the need of a covalent bonding between the nanoparticles, different manners of nanoparticles assembling with the same linker, higher thermal stability, cost effectiveness, and the capability to gradually control the degree of NR assembly, among others.